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Z. MONDAY SPEED CHANGER FOR KNITTING MACHINE Nov. 24, 1964 2 Sheets-Sheet 1 Filed April 9, 1962 'INVENTOR. Zephyr Monday ATTORNEY Nov. 24, 1964 2. MONDAY SPEED CHANGER FOR KNITTING MACHINE 2 Sheets-Sheet 2 Filed April 9. 1962 A TTORNE Y United States Patent 3,153,013 SPEED CHANGER FGR IQNETTING MACHENE Zephyr Monday, Mount Airy, N .C., assignor to U-Stretch Corporan on, Mount Airy, N.., a corporation of North Caroiina Filed Apr. 9, I962, Ser. No. 186,134 2 Claims. (Cl. 6656) This invention is concerned with speed changing apparatus for knitting machines and has special reference to a fluid drive speed changing unit to be operated between an individual motor drive or a line shaft drive and the conventional speed change pulleys or a single operating pulley of a knitting machine.

It is known that in many knitting machines such as circular machines only two speeds are normally available, namely, a low speed and a high speed and the knitting operations must be performed at either one or the other of these speeds. Consequently, many knitting operations such as those involved in knitting difierent parts of socks must be carried out at less than optimum speeds with accompanying loss in production as compared to what production would be if every such operation could be carried out at the most optimum speed.

Another known characteristic of conventional knitting drives concerns the fact that the various parts are so solidly linked together that a failure at one point is sometimes transmitted throughout the drive thus causing damage at several points. That is, conventional knitting machine drives lack shear pins, overload clutches or the like so as to break the mechanical linkage in event of failures or overloads.

With the above in mind, this invention has as an object the provision of a fluid drive speed changing mechanism for knitting machines which allows the obtaining of a relatively large number of speeds.

A further object is to provide a speed changing mechanism for knitting machines in which the pattern mechanism is employed to effect speed changes through a fluid drive.

Another object is to provide a speed changing mechanism for a knitting machine in which the line of power transmission between the drive motor or line shaft and the machine includes a fluid drive unit capable of temporarily breaking the link of transmission in event of faults, overloads and the like.

These and other objects of the invention will appear as the description proceeds and in the drawings, in which:

FIGURE 1 is an elevation showing a knitting machine having a fluid drive according to the present invention.

FIGURE 2 is a fragmentary perspective and schematic view showing the principal elements of the fluid drive of the invention.

FIGURE 3 is a wiring diagram of the control of the invention.

FIGURE 4 is a perspective showing an alternative means of switch control employing the pattern chain.

FIGURE 5 is a partial perspective showing the invention adapted to conventional speed change pulleys.

FIGURE 6 is a diagrammatic view illustrating an alternative arrangement of the fluid drive of the invention.

In general, the invention provides for a fluid drive to be interposed between the machine change pulleys or pulley and the electric drive motor or line shaft. The fluid system includes a fluid pump arranged in series with a fluid motor. The pump is arranged to be driven by the electric motor drive or line shaft and the fluid motor is arranged to drive the knitting machine change pulley or pulleys as the case may be. With the electric drive motor or line shaft in operation, the pump drives the fluid motor at its highest speed so long as the mentioned series fluid circuit is maintained and at the same time the machine pulley driven by the fluid motor is maintained at its highest speed. In order to vary such speed, the fluid system is provided with additional normally closed fluid paths in parallel with the fluid motor and each path includes a remotely operable valve that is controlled off the pattern mechanism. By opening and closing certain of these valves at particular times during knitting, various quantities of the fluid can be diverted prior to reaching the fluid motor which controls the speed at which the fluid motor operates and consequently the speed at which the machine pulley operates. Thus, as the pattern mechanism operates in its normal sequence, it is allowed to control the opening and closing of the mentioned fluid valves and thereby control the sped at which the fluid motor operates and in turn the machine speed in coordination With the particular pattern being knit.

As best indicated by FIGURES l and 2, the invention broadly encompasses the introduction of a fluid drive unit indicated generally at It). This unit may be driven either from an electric drive motor as at 11 or from a line shaft and pulley as at 8, 9 and thence through a connecting belt 12 and a pulley i3. Pulley 13 in turn is mounted on the shaft of a fluid pump 14- which acts as the power source of the unit. Fluid pump 14 is part of a fluid system which includes a connecting pipe 15, a fluid reservoir 16, a return pipe 17, a fluid motor 18 and a connecting pipe 19. The fluid system described is filled with the requisite amount of oil or other fluid suitable to fluid power transmission.

Overlooking for the moment the remaining apparatus shown in FIGURE 2, as the line shaft ll turns, pump 14 will build up a pressure head on the fluid in pipe 19 which in turn will be transmitted to fluid motor 18 so as to cause the same to be driven and the fluid returned through return pipe 17 to reservoir 16 and back to fluid pump 14.

As fluid motor 18 turns, pulley 20 which is mounted on the output shaft 21 of fluid motor 18 is caused to turn so as to drive belt 22 and the knitting machine pulley generally indicated at 23. With the fluid system described in operation, maximum operating speed is obtained. That is, with the pump, reservoir and motor in a continuous series fluid circuit and with all of the pumped fluid finding its way to the fluid motor, there is maximum transmission of power through the fluid and consequently maximum speed in the output shaft 21 of the fluid drive unit It).

While the particular arrangement described thus far does not by itself introduce speed variation means, this method of interposing a fluid drive does place between the line shaft or electric drive motor and the machine a fluid coupling such that the machine can be stalled temporarily and this coupling allowed to mechanically slip under such overload. That is, by matching the slip and torque characteristics of the fluid drive unit against the known stalled conditions of the particular knitting machine on which the unit is being installed, such slip effect can be matched to particular fault conditions. Consequently, the usual electrical overload switches, not shown, have time to operate prior to any extensive damage occurring.

Attention is next directed to the manner in which speed regulation is obtained. In this regard, 25 represents a connecting pipe extending from reservoir 16 to pipe 19 and which includes a normally open manual valve 26 and a normally closed solenoid operated valve 27. Pipe 25 is, in effect in parallel with pump 14. With valves 26 and 27 both open, pipe 25 will serve to divert fluid from fluid motor 18 and thus cause a decrease in the speed of fluid motor 18. Therefore, by choosing the dimensions of pipe 25 and valve 27 properly and leaving valve 26 open, the flow through pipe 25 can be regulated by energizing Patented Nov. 24, 1964- v J) solenoid valve 27 at predetermined times coordinated with the pattern being knit on the machine. Consequently, one means of obtaining speed regulation in output shaft 21 and pulley 23 is to open and close valve 27 in time relation with the pattern being knit.

Referring further to the drawings, 23 represents an additional connecting pipe between reservoir 16 and pipe 19 and which is in parallel with pump 14. Pipe 28 includes a normally open manual valve 29 and a normally closed solenoid operated valve 39. As will be appreciated from the explanation previously given in connection with valve 27, with valve 29 always open, the opening and closing of valve 36 by itself or in combination with valve 27, otters an additional means of speed regulation in that additional fluid can be diverted by means of valve 30 when energized and consequently an additional increment of speed reduction relects itself in a change of speed in pulley 23. Here again, by proper choice of pipe and valve sizes, given quantities of fluid can be diverted by operation of valve 30 and a predeterminable speed change L obtained.

In addition to solenoid valves 27, 3t and pipes and 23, the fluid drive unit includes a third pipe 31 having a normally open manual valve 32 and a normally closed solenoid valve 33. As with valves 27 and 39, additional speed regulation is obtainable by opening valve 33 through energization of its solenoid in time coordination with the pattern being knit.

Various means for energizing solenoid valves 27, 3 and 33 are available. However, it is important that the means chosen be coordinated with the needs of the pattern being knit. For example, when knitting socks the machine speeds should be coordinated with the make-up courses, top courses, heel courses, foot courses and toe courses as each of these groups of courses frequently demands a dilierent cylinder speed during knitting. By way of illustration, there is represented in FiGURE 2st 34- a section of pattern drum having suitably placed cams at 35, 36 and 37. As those familiar with the art will appreciate, control cams such as earns 35, 36 and 37 will not necessarily be positioned as illustrated but rather will be positioned on drum 34 according to the type fabric and machine employed.

In operative association with cams 35, 36, 37 are three separate normally open micro-switches 38, 39 and 43. While not shown in detail, it will be understood that micro-switches 33, 39 and 40 are supported by suitable means fixed to the machine so as to be actuated by the particular cams with which each is associated. This is illustrated by the representative bracket 41 shown in FIGURE 1.

As drum 34 rotates in step with the pattern being knit, particular cams on the drum are arranged so as to contact either singly or in combination the various switches 38, 39 and 40. As a particular switch is contacted and electrically closed by a drum cam, a circuit is completed from a low voltage supply lead as schematically indicated at 42, FIGURE 3, through a low voltage relay, as indicated at 43, with which the switch is in series and to ground as at 44-. Thus, the closing of switch iii acts to energize low voltage relay 43 which in turn acts to close contacts 45, 46 and energize valve 27 causing it to open; the closing of switch 39 acts to energize and open valve and the closing of switch 38 acts to energize and open valve 33. Flow through pipe 25 is thus controlled by switch flow through pipe 28 is controlled by switch 39; and flow through pipe 31 is controlled by switch 33. Each of the switch positions are however dependent on the pattern mechanism so that it is the pattern mechanism which ultimately controls the speed of the fluid drive unit 10 and therefore the speed of the machine. As indicated in FIGURE 3, the valves 27, 3G and 33 are operated at relative high voltage such as 110 volts, alternating current which insures fast and positive action. The Control circuits however are operated at low voltage to minimize the risk of shock to the machine operator.

In addition to utilizing one of the pattern drums as a means of controlling switches 38, 39 and 40 it is also contemplated that the pattern chain will prove a useful control point in many machines. FIGURE 4 illustrates this embodiment in which 47 represents the usual set of change cams found on the pattern chain for purposes of changing operations. Depending on the particular speeds, their timing and the like, cams 47 may be found to be applicable to control of switches 38, 39 and 40 in their conventional form without requiring that they be changed in location on the chain or in their operating characteristic. That is, with some machines, switches 38, 39 and 4% may be suitably bracketed to the machine as for example at 48 and the conventional chain cams 47 used to actuate these switches. In other types of machines, additional chain cams will be found necessary and in other cases it is contemplated that some of the switches 38, 39 and 49 will be operated oif the pattern chain while others are operated off the drum.

While described in connection with electrically operated solenoid valves, air operated valves and air operated switches as well as other equivalent devices may be used for the purpose of regulating the fluid drive unit 10. In some applications, the fluid drive unit 10 will be the only source of speed change. That is, the fluid drive unit 10 may be employed in connection with the usual change pulleys as illustrated by FIGURE 5 so as to superimpose the speed change possibilities of the fluid drive unit on the conventional speed change mechanism rep resented by pulleys 49, 50, 51 and shifter fork 52. Patent 1,152,850 issued September 7, 1915, to R. W. Scott explains one form of the now well known operation of such change pulleys. Alternatively, the fluid drive unit may be connected to a single drive pulley on the machine as at 23 so that the speed depends entirely on the positioning of switches 38, 39 and 40. In either case, it is of course necessary that the particular switching means used to be operated off some part of the pattern mechanism such as a pattern drum or pattern chain in order to keep the opening and closing of valves 27, 30 and 33 in time relation with the knitting sequence.

While belt drives as illustrated by use of belts 12 and 22 are customary and offer various advantages to knitting machine operation, it is contemplated that some applications of the invention will lend themselves to direct drive as schematically illustrated by FIGURE 6. That is, the drive shaft indicated by 53 may be either an individual motor shaft or a line shaft and it may drive the fluid drive directly without use of a belt. Furthermore, the output shaft indicated by 54 of the fluid drive may drive the knitting machine directly without requiring either pulley or belt on the machine itself.

Having described my invention, what I claim is:

1. In a knitting machine having knitting mechanism powered through an input shaft on said machine; a drive shaft from which said input shaft is driven; a liquid fluid electrically controlled speed change mechanism interposed between said input shaft and said drive shaft including a fluid motor driving said input shaft, a fluid pump driving said motor and driven by said drive shaft and pipe means adapted to bypass pumped fluid around said motor; remotely operable electrically controlled valve means effective to open and close said pipe means almost instantaneously; and a pattern mechanism including control means effective to operate said valve means at predetermined times whereby to control the amount and timing of said fluid bypass and thereby establish the speed sequence of said machine in coordination with the operation of said pattern mechanism.

2. In a knitting machine having knitting mechanism powered through an input shaft on said machine; a drive shaft from which said input shaft is driven; a liquid fluid electrically controlled speed change mechanism interposed between said input shaft and said drive shaft including a fluid motor driving said input shaft, a fluid pump driving said motor and driven by said drive shaft and a plurality of bypass pipes each adapted to bypass a portion of the pumped fluid around said motor; a plurality of remotely operable electrically controlled valves mounted on individual ones of said pipes; a pattern mechanism including control means effective to individually operate predetermined ones of said valves almost instantaneously at predetermined times whereby to control the amount and timing of said fluid bypass and thereby establish the speed sequence of said machine in coordination with the operation of said pattern mechanism.

References Cited by the Examiner UNITED STATES PATENTS Peaslee 103-41 Lieberkneckt 66-82 Stacy 60-97 Connor et al. 60-52 Riddle 60-52 Lawson 66-56 Bolliger 74-687 RUSSELL C. MADER, Primary Examiner.

DONALD W. PARKER, Examiner. 

1. IN A KNITTING MACHINE HAVING KNITTING MECHANISM POWERED THROUGH AN INPUT SHAFT ON SAID MACHINE; A DRIVE SHAFT FROM WHICH SAID INPUT SHAFT IS DRIVEN; A LIQUID FLUID ELECTRICALLY CONTROLLED SPEED CHANGE MECHANISM INTERPOSED BETWEEN SAID INPUT SHAFT AND SAID DRIVE SHAFT INCLUDING A FLUID MOTOR DRIVING SAID INPUT SHAFT, A FLUID PUMP DRIVING SAID MOTOR AND DRIVEN BY SAID DRIVE SHAFT AND PIPE MEANS ADAPTED TO BYPASS PUMPED FLUID AROUND SAID MOTOR; REMOTELY OPERABLE ELECTRICALLY CONTROLLED VALVE MEANS EFFECTIVE TO OPEN AND CLOSE SAID PIPE MEANS ALMOST INSTANTANEOUSLY; AND A PATTERN MECHANISM INCLUDING CONTROL MEANS EFFECTIVE TO OPERATE SAID VALVE MEANS AT PREDETERMINED TIMES WHEREBY TO CONTROL THE AMOUNT AND TIMING OF SAID FLUID BYPASS AND THEREBY ESTABLISH THE SPEED SEQUENCE OF SAID MACHINE IN COORDINATION WITH THE OPERATION OF SAID PATTERN MECHANISM. 